Telephone-exchange system.



R. H. MANSON.

TELEPHONE EXCHANGE SYSTEM.

APPLIOATIOF FILF D XAB. 2B, 1907.

8 no: u to:

3 SHEETS-SHEET 1.

Patented Mar. 15,1910.

R. H. MANSON.

TELEPHONE EXCHANGE SYSTEM.

APPLIOATIOK TILED EAR. 28,1907.

Patented Mar. 15, 1910.

3 SHEETS-SHEET 3.

lvihwaaea R. H. MANSUN.

TELEPHONE EXCHANGE SYSTEM. APPLIGATIOF TILED XAB.28,1907.

952,267. I Patented Mar. 15, 1910.

3 SHEETS-BREE! 3.

, InvEn DI \qg/hffia 258B REE 1 1713 115011 AIIurnE s and the wanted subscriber. \Vhen the lat- To all irhom may concern:

tervals, a separate and distinct relay re- ..-,cc .ording to still another arrangement, ringing current and battery current are alternately fed to line through the control- UNITED STATES PATENT OFFTCE.

BAY H. MANSON, OF ELYRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRIC COMPANY, OF ELYRIA, OHIO, A CORPORATION OF OHIO.

TELEPHONE-EXCHANGE SYSTEM.

Be it known that Ll-lar ll. Manson, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

Myinvention relates to telephone exchange systems, and has for its object the improvement of such systems in divers particulars to be hereinafter pointed out.

The present invention has to do particularly with the devices and circuits through which signaling current is sent to the station of the wanted subscriber, and by means of which the source of current is disconnected or disabled when its function has been performed. In most cases this latter is best determined by the answering actof the called subscriber, but is not necessarily limited thereto.

Heretofore, various arrangementfhave been proposed to accomplish the results which I compass, but so far aslknow these have ben only measurably successful in practice. For example, according to one arrangement an electromagnet is included in the. ringing circuit between the generator ter answers, the consequentv rush of ringing current through the low resistance path of the receiver and transmitter branch etl'ectirely energizes this clectromagnet, which acts to cut oil' the ringing gencrator. The ringing through this magnet is not as good as itwould be through a clear circuit, because of the choking efi'ect of the magnet, windings; and in ringing over a very short line or over one which has become short cir cuitcd, there is great danger of burning out the magnet. According to another arrangement. the ringing current is put on atinsponding to current in the subscribers hues and controlling the ringing between the intervals. The disadvantage of such an arrangement is that if the subscriber answers while the ringing interval is passing, the ringing current will produce very disagreeable etlects in the receiver held to his ear.

Specification of Letters Yatent.

Application filed Batch 28,

Patented Mar 15, 1910. 1am. SeriaiHo. 385,001.

ling devices. With such an arrangement, it is necessary in producing uniform results to have an approximately uniform voltage, which cannotbe supplied by the ordinary common or talking battery for the reason that the ringing voltages are usually much higher than thatof the talking current. Moreover, there is some danger of ringing current getting back on the main battery busses, with disastrous results so far as conversation is concerned.

As distinguished from all of the foregoing arrangements, my present invention employs (1) non-inductive controlling devices in the ringing circuit, (2) such devices being arranged so as to respond instantly by cutting oti ringing current when the called subscriber answers; and (3) a driven source or an alternating current. generator of any suit able frequency to replace the battery formerly employed between the ringing intervals' My controlling devices preferably consist of thermic relays, commonly called hotwire relays These relays, or one of them,

must be included direct in the. path of ringing current, or of other current going to line during ringing. Instead of a battery for non-ringing intervals, I employ a suitable alternating current generator for furnishl mg tripping current, of a frequency such that it will not operate the bells on the lines.

1 u s whereby false signals will be avoided on party lines. This tripping current and theringing current are putto line' through suitable commutator or other form of controlling device.

My invention is illustrated in the accompanying drawings in which- Figure 1 is a diagram showing two subscribers lines and the central station con ncctiug circuits therefor, one line being extended to a single substation, while the other is a party-line. Fig. 2 is a side view and Fig. 3 isan end elevation of a form of selective ringing key which may conveniently be cm loyed.' Figs. l and 5 are modified detai ed views of parts of the apparatus shown in Fi 1.

Referring first to Figs. 2 and 3, I have therein shown a four-party selective key of the locking type, wherein each of the four lungers controls a pair of contacts included in the circuit of a particular ringin generator. These plungers are marked 1?, k; k

i --S, an: the rvln zs R L. R" R, with the :iilliil; l'mtl'm v l5 huIWr-en (hum, having its. w'n :iry of ihrm z gmaiiivv fizrminnl grmiuilwl ':is usual. The

- l M" R, R are hlll'lliOE-ltl in jointly control 11ml 11'. Al film and of 'ihv frame 1 l mvnie i1 air hf C(Hil of he uihe are fully cios 1,: W, rvl: lune three pm in their first Lln', pflz illufi, in which than 11"., :shmrn in llH: 3 plug l, while IlHjri-lzn's ll", R similarly figures, the are all the way up. In their i-nntrul ilk"Sllpti" i$()1'\' hump :issnciated with sz-snml-gnexlic n they urn. lui'chuil, :zml in the plug 1". thcirlhir l pasitiun cru'h one: n'nlu t ClUSC' 'l'hi rin Q, Q, cm, are adapted to he the cirnuit [If lhv Lfi i springs 11" hy ftilljlllg i :n-uauleil liy 121031]: of viii-rent furnished by haul; the hii i phur- 'lhv lzzlchiu! iw {he ringing gvnvrah'zrsfi. i'r' (lr"G ,fii1il llie ell'ecievl by ihu ends of the screws Z". which mun,- i: i triw of the ringer Q" with respect extend our from he pining-31s tug, g0. the i .i) n'..:' part" unr gvnvrumr. :13 for exnmplv hush plaid, hast shuns in n "(hen (2. l slmnfl'l hr; 1 e that while -I have nu um: plungzri ihvil and shall Spel -r 13 7 claim the zippzirn-us and circuits nun: dun; Q z in :isv my inwntinn for poly sill- 4 it 'ry no means linnieil far: is broadl zippliczibh" in In an ringing, the wl in he broken by iho mg he El. win 2 members in, m, m, .Jgirrnie with H-"mimlcontacfiof the wires I, 12- I so lint nurnxinly the con- Referring now Fig. l, .i A. \rv Judi-w" fl g ns to ihrplug P by way of the snbfluiinns, un-L-h pruvi .2 will: ih l ire 13, While 1hr (filill lfifil also passes common lmttnr) equipment )l' llig rv: in i'hv plug by way of the wire ll. When cv'rur, lrunsinittcl, hunk-1 itch. ri ain'- hey Jul i: :wluulvri, the lip of the plug l." cun lnser. The suhslati-rm -3. v vonniacic-il thrfl'tgh wires 13 and 12 to the line 1- extcniiing to the ccuiml 01hr; iilti llli j relay )I and so to the riirging gem terminafin' on the niulri in juclv J J of :i ilulil'l wire 9. .\t the mine time, the der ve manual lfchlmurd. The. slain 1 A, on if the plug is lL(lIHU .l to ground through the uthcr hand, is one of four qnlinns survlhr win-s 32S and IT. [he key M is conhy the name linv, and typified by the ring irnilml h the Lhvrmul dciicc M Similar in (Q. Q, Q and Qj bridged ncrn zthe lin its HICClizUliifll rrnnsl'ructirm to the relay M. The slil slzllioli uquipinent iliflution A The cuntrulling (ll-rice hzi a p n-uteri lever supposed to hi: zissuiziutrrcl with ihi: v: :ivh Willlx'n the. lwy M, this lever iving ringer Q, and eauh of the uthr ringers l\'()[(.':!l in ihv Hll (l(ll :uul cminectvil on lmth HSFfiClHtEd with .-;iniil;ir cquipmunr. nut la; of tin: pivot h \Ylll'S 15' zinil t0 the siiuwu. This 'wly-stzztion nr pnri \-'-linv. unil n1 :1 v lrziin piu'i: m, which i. provi luil marked 34, oxtenm in :i s nin;; jm-k 11 \llll spring in her-p the wires taut. Sinrc jacks J at he rcnlgrai mic h-nih wires are "Kllfirlll equiilh' to the ilihlHS I have not :hmvn any direct mnnuulinn i plirrv. I'm-y remain relatively unnllucleil h from lhc main lnriiizry l; in vithr-r (if rlw i 'liJHfWS in i-xlvrnzil lmupvrzilurv, hut thilinrs l-;2 or 3- 1, llQillii'I hura l nhmrn :i 3 minlJ is iuvhulvil in a c-iintrnlliug ciruilv line relay, a cut-(ill relay, (:r 1: line lump -fur lhu key M which may be traced as fulcuntrnllcd by the line relay, Wllhih in turn Lin- 1 l'rum thogrmind by wire 22 inthn Roy is controlled by the cut-oil rnlay. 'l'hvw Q minim-is is lit-(5 Fig, 3). Q1, 19, If? -l. appliances ful'lll no pan of my FI'VSLH. iuf :uul gmuml. \Yhvn {he suntan-is 1: are vi-miun, :Hh'l may lhvrrzl'nrihe. of any iii-ll hwwl lhrrvl'm'c. vurrcul passvs through lhv lcumrn or .-uil:ililv \nn'hivh will \wrl; wire 1 in hnul the name. whvrehy the he prop-ll \viih lhusc purlinns ii in uril vir M is :irrluziiml. :lIHl :i lurking circuit to lfl 'l) cHil whi l; :irv mx'ulx'ml in tin: m-wu: n- Ziw xvii-P 1) Warm lhvn clusmL whir-h may \vmiou. lt will he izinlvrmm l that l 21- l'm li'ui'wl as l'nlhnvs: hauler) B. 23, 19. 1 EQLVG to ni -lf the full right in rumplvlv 211-, l-l. m, 11/, 15,1i1ul griuuul hack in lnl- Lhu equipment of the lini-s so 215 l inrlnilu ivrr. 'lln- L'OIIllNiS m" and m are unilvr llH all HLUl .lall'V and usual liiu: anal :Hlfi utlzvr mmrnl of lhu !"l:t )l. 'hivh has :1 pair u? :ipplizir sfwithnut liuiilzilwu hr rmswu nl' nirvs ill will ll mung-Mull :rl (m0 l'lHl t0 the the simpliliwl diagram herein. tr.iin plain m and at the uihi-r tn uppiblll Fur inicr-x-iniu-ding lhv lines lshuw :1 air minlz m) ilw pivntml lever in, i-unlrulliug of phage E. l, cunniwlml hy the mril cunrim minim-h 1:1. 11/. Thv \rirv l) is in- (luctm's (i -G. T whirl: izn-lmlc the cuui 'lllillll in the L'l'l! ":at r mum-Minn H --l' m rlvnSers (F hulwwn lhom. 2 :2. in ilivi hhe hp 20- Ill .Hul i SlHHlHIl h an vq mlizvr 1'. cur l ll puff-"Ev: whiz-h nun h" uiiher n ('HIHhliSN' of Mlitaihh across the inn ends r aurpnrii :i intml ulilu'l 'l having its irnu vunn mperrhiury lump :issnvinlml will) the l i t l 7 l l l manually circuit designed so as to he more etlicient at one frequency than at another, or the lila as shown in Fig. 4. "he theory of this equalizer is that the amount of currentshanted will vary with the frequency or the voltage, or both. so as to render the amount of current flowing through the wire 10 approximately constant for all frequencies and all conditions.

For single-party ringing, the genemtor wire 5) goes direct to a single machine. For example the circuit from the key )1 would he as follows: 12, l0, 9. 32, XI and ground: with an alternatively closed branch 25 through generator G to the ground wire 26. H is a special generator for supplyiag tripping current which will not produce any disturbing ettects in the line, Its current will not ring any of the hells Q", Q. Q'. Q or (1 but it will heat the wire 1 of relay M, just the same as the current ot the generator G. c.

The generators G and G are put on alternately hy means of the commutator X, which is supposed to he constantly rut ting, but which may of course he operated intermittently or in any desired manner. the. called subscriber answers, the relay )l' i supposed to he energized to open the contacts m m. and to thereby release the ringin; key M hy cutting off the current of the controller M". For ringing a single part). it is requisite to have only one pair of operated contacts, \'i7.., those at if.

For polystation ringing, the arrangement is the same as for single station ringing after the proper generator has been con nectcd to the a he 3), and this is the function of the hey K. As a matter of convenience, I cause the depression of any one of 'the selective hers is. Z", 7:", F. to also close the contacts is, so as to complete the circuit 532. :31. 19. l, 2-1, thus stunting the ringing by pulling down the key M in the performance of the ame act which determines the station to he called.

have shownjour commutators X. X. X, X wh ch are supposed to he mounted on the same :lr... ..nd all run together. They ma of course he replaced by a single commutator X hthe wire 9, the contacts of the keys 7., 7; Zr", if, then going -direct to the generators G. G. G (i as shown in Fig- The operation of my system is followse-Assuming that subscriber A calls, lights his line lamp and is answered by the insertion of plug P, which extinguishes the lamp, and that the operator has obtained thenumber-wanted and has inserted the -alling plug P in the jack J of the wanted line, then we come to the ringing, wherein the present invention resides. I will first assume that the ringing is to be selective, in that one of the ringers only, as Q, is to be actuated. The operator presses down the plunger l', which closes the contact k to connect wire 32 to wire 9, and also closes contact If. A circuit is thereupon complcted for the flow of current through the controlling device M", as follows: B, 23, 19, 21, Zr", 22, 24 and hack to battery. The wire 9 expands, and as the strain plate m" is kept taut and level by its spring, the lever m is tilted to prc. down the ringing key arm in, which carries with it the other arms m, of, disconnects conductor 6 from wire 13 and conductor 8 from wire 16, and completes the following ringing circuit: generator G, 28, n, 32, it 9, 10, 12, m, 13, l", P, 3. to the ringers, l, J, P, 16, m", 17, and ground hack to the generator. As the commutator N rotates, an alternative circuit is closed as follows: generator G, a, 3-2, is", 9, 10, 12, m, 13, 1", J", 3, ringers, 4, J P, 35 16, m 1?, ground, 26, (5*. The ringers Q, to Q} are wound to such a resistance in each case that the amount of current which will pass through the circuits thus traced, either from generator G or from generator 0:, is insufficient to heat the wire-10 to the point of expanding so as to actuate the spring m"; The generator G furnishes current at a proper frequency or a proper voltage, or both, to ring the hell Q only; while the. gencrater G furnishes current such that it will not ring any of the bells. I have shown this generator as an alternator, and it is supposed to furnish alternating current at a frequency or a voltage or both to which the. ringers are irresponsive. Of course the char; acter of the current may he 'aried in man ways in order to produce this effect. There is a strong tendency however in modern enginet .ig practice, to make all the ringers in a system standard harmonic type, so that they all have definite frequencies to which they respond. The most advantageous because the simplest 'ay to design the tripping generator G for such a system is to make it an alternator with a frequency similar from any to which the ringers in this system will respond.

After the operator has pressed down the key 7r, it remains latched, and so the ringing 115 and tripping current continues to flow to line as determined by the commutator N, un-

til suhscriben Y takes down his receiver. When he does this, a circuit is closed through his receiver and transmitter, whichare of much lower resistance than the ringers. A rush of current follows. through the. line wires 3-4- and through the wire 10 of the relay M. The wire 10 expands, the levezzm becomes tilted thereby, the contacts 'm, m are opened and the controlling circuit or locking circuit of the ringing key M becomes ino erative. This controlling circuit is close as soon as the key M is first set by the closure of contacts In", and nifty be 139 traced as follows: I3. 2-"). 19, 18, m. M, at, l {tam, 15, ground, 24, B. This circuit being opened, and the springs If remaining open, the wire 1!) immediately cools oil, the lever to becomes straightened on its pivot, the key .\I resumes its normal position as shown in Fig. I, the generat r circuits are disconnected from the cord. and the cord circuit is completed for conversaiou.

In ringing out over a is'in e station line the operation is precisely the same, except that only one generator is employel, and there s no necessity for a selective key. In other words, where there is to he no partyline ringing, the Qt'tlctatotS G, G G may be dispensed. with, together ith their commntators X. X, and all of the keys 7r, 7.", It": If. The circuits up to the relay M would then be direct as follows: g nerator G by wire to segment nv on the cennntttater N and thence by wire 32 to wire 9 direct, "enerator G by wire 25 to the Fug tucnt n of commutator X, and thence by wire direct to wire J. The operator needs only the contacts N, which are normally open but are closed just lo'tg; enough to start the thermal controller M The same result of course may he obtained mechanically h puttin; :1 met hanical pushbutton on the ringing key M an that it can be forced down by hand, current flowing;

through the circtiit B, l3, l9, 18, m ll, 15, then serting to hold it down.

At station A l have shown the ringer permanently bridged on the line, the ringers at the other stations on the same line being similarly connected. At station A the ringer Q is disconnected when the. receiver is on the hook.

It :viil be apparent that many changes in matter of detail may be made in the system I have thus described. without altering the main or (ll:\I.lL'ttIi:llC features of my invcntion. All such changes I contemplate as within the scope of my claims. Thus, a different arrangement of keys, relays, or couunntators might be employed, without altering that part of the invention which relates to the trippin; generatotx-stlr different kinds of generators could be employed, perhaps diti'ercntly connected or constructed. without altering the character of the structures M, .\l'-, or their combin d use it: the relations described. ()r changes might be made in the character of any individual piece without changing the combination of all of them. It should be ohscrved that as the connnutators rotate a ringin; generator is connected to line for a space ay of two seconds, which rings the hell or bells. then the other generator comes in, which still furnishes current to the line through the relay M, but the bells are silent for say four seconds. This i called in contmercial parlance, ring two se onds and oil .I contemplate in some cases coinluning th 'IOIltIillUt'S (l and G in one unit, simply (211E111; a change to be brought about in the character of the current cutput at intervals so as to silence the bells.

It should also be t.-bserved that by using driven generators for bo h ringing and tripping. we are enabled to u e approximately the same voltage and fretptency, or at least voltages and frequencies of the same order. If the ordinary genemtor G gives volts, and the asso iated generators vary from that to 1-30, the generator G" may advantageously he made of some intermediate voltage, and so with the frtn'ptcncics. This however is purely optional.

Having thus described my invention what l i'lllllll and desire to secure by Letters Patent is;

1. In a telephone system, he combination with two telephone lines connected together, of a key adapted when depressed to include a calling generator in circuit and Simultaneously open the connecting circuit and thcrntic means adapted to engage and to main ain said hey d pressed until the called subscriber remove; his telephone from the hoe-h.

2. In a telephone system, the combination with'two tclephone lincs connected together, of thermally operahle means adapted when actuated to include a calling generator in circuit and simultaneously sever the connecting circuit, and thcinally operable means adapted to engage and maihtain said first named means in actuated position until the call d subscriber removes his telephone from the hook.

3. In a telephon system, the combination with two telephone lines connected together, of a key adapted when actuated to connect a calling generator in circuit, thermic holding: and releasing means adapted to engage said key and means. whereby the called subscriber may determine the operation of said holding and releasing means.

i. In a telephone system, means for connecting two lines together, a thermal ringing relay, :1 manual setting device therefor, a thermal tripping device therefor, and means wln-reby the called ubscri er may actuate the tripping device in answering the call, ulzstanlially as described.

In a telephone system, means for connet-tin; two lines together, a thcrnial ringin; relay. a manual setting device therefor, a thermal tripping device therefor, a ringin; generator and a tripping generator, means for connecting them alternately to the thermal tripping de .'i"-e, and m ans con- 

